Latch means



W. J. CLARK Oct. 18, 1960 LATCH MEANS 2 Sheets-Sheet 1 Filed June 21, 1957 IN1/Ewan wu/Aw 7. cmfr nef/vr w. J. CLARK LATCH MEANS Oct. 18, 1960 2 Sheets-Sheet 2 Filed June 2l, 1957 Fvg. 6.

2,956,828 Patented Oct. 18, 1960 i nitec'i gratas LATCH lVIEANS Wiiiiam .1. Clark, Philadelphia, Pa., assignor to Philco Corporation Philadelphia, Pa., a corporation of Penn- Sylvania Fiied .lune 21, 1957, Ser. No. 667,200

10 Ciaims. (Cl. 292-2515) The present invention has to do with latch means and more particularly to latch means for doors. While of broader applicability, the latch means of the present invention has particular utility in the yfield of refrigerator cabinet structure wherein resilient sealing means is provided between the door and the cabinet.

It is an object of this invention to provide positive and smooth latching means actuatable by merely applying a light closing force to the door of a cabinet.

It is another object of this invention to provide latch means in novel combination with a door provided with a low-pressure sealing gasket.

It is still another object of the invention to provide magnetic latch means having mechanism cooperable therewith to facilitate overcoming the magnetic force of attraction while opening the door.

It is a feature of this invention that the latch means is so constructed and arranged as to permit easy opening of the door in the event of an emergency.

Another feature of this invention resides in the novel construction and arrangement of a door latching means whereby the door is effectively prevented from rebounding in the event it is slammed.

Still another feature of the invention resides in the construction and arrangement of the novel door latching mechanism wherein there is no latch adjustment required in the event the door should sag.

In the achievement of the foregoing and other objectives, a preferred embodiment of this invention comprises magnetically interengageable magnetic latch and keeper elements in novel combination with means operable in response to interengagement of said elements to urge the door to closed position.

The manner in which the objects and advantages of the invention may best be achieved will be clearly understood from a consideration of the following description taken in conjunction with the accompanying drawing in which:

Figure l is a perspective showing of a refrigerator cabinet embodying the present invention;

Figure 2 is an enlarged fragmentary sectional View of apparatus of the kind shown in Figure l, the view illustrating the door and cooperating latch means in lthe open position;

Figure 3 is a view similar to Figure 2, and showing the door in the closed position;

Figure 4 is a somewhat diagrammatic fragmentary view, in perspective, of a modilied embodiment of the invention;

Figure 5 is a view similar to Figure 4 and showing an operational feature of the modified embodiment;

Figure 6 is a somewhat diagrammatic fragmentary view, in perspective and showing still another modification of the present invention; and

Figure 7 is a view of the embodiment shown in Figure 6 and showing an operational feature thereof.

Now making more particular reference to the drawings and especially to Figure l thereof, it will be seen that the invention is shown as embodied in a household refrigerator which comprises a cabinet 10 having an outer shell 11 and an inner liner 12 defining a storage compartment 13, and access to which is provided by a door 14 hinged to the front of the refrigerator. The aforesaid shell 11 and liner 12 are spaced and insulated from one another by means of suitable insulation 15 (see also Figures 2 and 3), and as is customary breaker strips 16 of low thermal conductivity extend about the forward edge of the cabinet and bridge the gaps between the shell 11 and inner liner 12. The door 14 comprises outer and inner panel members 17 and 18, respectively, which are maintained in spaced relation from one another, and these members are insulated one from the other by means of suitable insulation (not shown). A suitable gasket strip 21 is aiiixed to the inner surface of door liner 18 by known means and is adapted to bear against the front edge portion of refrigerator shell 11 thereby to form a seal with the latter. A suitable xed handle 19 of known design is provided on the outer panel 17 of the door, to provide holding means for an operator to open and close the same.

In particular accordance with the invention, and referring further to the embodiment shown in Figures 2 and 3 of .the drawing, there is provided a novel combined magnetic-mechanical latching means 22, preferably of the self-cocking type, for retaining the door in its closed position. rThe embodiment illustrated includes armature means 23 aixed to cabinet 10 in the region of left hand breaker strip 16 and forming a strike plate cooperable with extensible and retractable magnet means 24 carried by a link 25 of the over-center mechanism 26 disposed within the door adjacent a vertical free edge portion thereof. Preferably although not necessarily, resilient pads 2t), Ztlb of rubber or the like are provided intermediate the armature 23 and its supporting structure as well as between the magnet 24 and its supporting link 25. Also, it is to be understood that the term armature means is intended to include magnetic as `well as magnetizable materials, as may be found best suitable. The over-center mechanism 26 comprises a frame 27 aixed to the door, and pivotally mounted to the frame by a pin means 31 is link 32 provided with a cam-like portion 33. Pivotally axed to the aforesaid link, as seen at 34 at a point spaced from the pin means 31, is a link 35 adapted for both pivotal and slidable engagement with the pin means 36 aixed to the frame, by means of a slot seen at 37. A compression spring 41 is disposed along link 37; the spring 41 is extensible or retractable in response to pivotal-sliding movement of the link, to urge the link 32 to either a full right hand or left hand position, by virtue of the over-center action of cooperable links 32 and 35. Additional structure includes a slot 42 provided in extensible and retractable link 25, slot 42 being disposed for registry with fixed pin 31. Similarly, a slot 43 is provided in frame 27, and extends co-linearly with slot 42 formed in movable link 25; a pin 44 is provided in link 25 and in registry with slot 43. Thus it is seen that the construction and arrangement of the aforementioned slots and pins accommodate telescoping movement of link 25 with respect to frame 27 thereby providing the desired extensible and retractable movement of the magnet 24. As best seen in Figure 2, movable pin 44 is a cam follower for cam-like portion 33 of link 32, whereby outward movement of the link 25 urges pin 44 against portion 33 to rotate link 32 about its pivot 31 thereby compressing spring 41 and forcing interconnected links 32 and 35 through dead center, whereupon spring 41 takes over and urges link 32 to its full righthand position, as determined by a suitably formed stop means comprising extension 45 of the pivotal link 32 and pin 44.

As best seen in Figure 3, the hereinbefore described mechanism has been fully retracted to maintain the door in its closed position, reacting against the force of attraction existing between armature 23 and magnet 24. It is seen that spring `4-1 now urges the link 32 in an opposite direction to that shown in Figure 2. The spring force is sufiicient to compress gasket 21 to seal the door to the cabinet and prevent excessive rebound of the door during closing of the latter, but is not sufficient to overcome the holding force between the interengaged magnet 24 and armature or keeper 23.

In describing the operation of the novel latching means hereinbefore described, attention is directed to Figure 2 wherein door 14 is open and the latch mechanism 22 is disposed in its fully extended position. As the door moves toward closed position, magnet 24 moves toward keeper or armature 23, as indicated by the arrows, followed by engagement of the keeper and magnet. Continued closing movement of the door forces the magnet and its supporting link 25 toward the door, and pin 44 is thereby urged against extension 45 of the link 32, to pivot the latter and operate the links 32 and 35 through dead center and into the latched position shown in Figure 3.

To open the door, opening force is applied to the handle i9, and the force of attraction between keeper 23 and magnet 24 is of a value equalling or exceeding the mechanical holding force of the over-center mechanism. The result is that outward movement of the link Z5 relative to the door moves pin 44 against cam portion 33 and rotates links 32 and 35 past dead center. There follows movement of the mechanical linkage to its fully extended position under the influence of spring 41. A continued pull upon handle 19, as well as the momentum of the moving door, will then effect breakaway of the keeper 23 from the magnet 24.

Now referring to Figures 4 and 5, a modified embodiment of the present invention is seen wherein the novel combined magnetic-mechanical latch 22a includes a keeper, or armature 23a provided in the door 14a, as best seen in Figure 5. Keeper 23a is aixed to the inner surface of door liner 18a by suitable known means, adjacent door gasket 21a, and overlying an aperture 28a in the liner; there is disposed between the liner and keeper resilient pads a of a known suitable material, for example rubber. The novel combined magneticrnechanical latch 22a further includes magnet means 24a provided with pole pieces 29a, one of the latter being received in a suitable guide means 30a atiixed to cabinet shell 11a and having generally lC-shaped cross section whereby the magnet is retained for extensible and retractable sliding movement. Such movement of the magnet is accommodated by a rod 38a afiixed at its one end to the magnet means and at its opposite end to a suitable over-center latch mechanism 26a which may be of well known design and afiixed to the rear wall of cabinet outer shell 11a.

Operation of the hereinbefore described modified embodiment is similar -to the showings of Figures 2 and 3 already described. More specically, and referring first to Figure 5, the door 14a is seen in its open position and the latch mechanism 22a in its fully extended position, as defined by the illustrated position of over-center mechanism 26a. Closing of the door causes keeper 23a to strike pole pieces 29a and adhere magnetically thereto, followed by continued movement of the door to its fully closed position, as represented by the position of keeper 23a .in Figure 4; in the latter figure the magnet means 24a is seen to have been urged to its fully retracted position through the action of over-center mechanism 26a.

To open the door, the fixed handle 19a is pulled, thereby overcoming the holding force of over-center mechanism 26a (the same first having been extended to the position shown in Figure 5) followed by overcoming the magnetic force between keeper 23u and magnet pole pieces 29a. The magnetic holding force is, of course, equal to or greater than the holding force exerted by mechanism 26a.

Still `another and somewhat more simple embodiment is shown in Figures 6 and 7, wherein the keeper 23b is seen to be cooperable with pole pieces 2917 of a magnet 24b. The outer, or non-retained pole piece is seen to have a rearwardly extending portion 29e provided with a cam surface 33h. A cam follower 44b is carried by a link 32b pivotally mounted to liner 12b by a suitable pin means seen at 31b. A spring 41b is so constructed and arranged as resiliently to urge cam follower 44b against the cam surface 33b, and against a horizontal portion 33C of `the pole piece extension. It is to be understood, of course, that the forwardly extending portion of cam 33b, as seen .at 33d, may be formed to provide, in cooperation with follower 44b, stop means for the magnet means 24b in its fully retracted position yet permitting a constant pull-in force by the latch against the compressed gasket of the closed door.

Opening the door from the closed position seen in Figure 6 to the open position illustrated in Figure 7 moves magnet 24b to its extended position in which cam surface 3319 and follower `44b cooperate to urge arm, or link, 32b upward against the force of spring 41b. Continued withdrawal moves follower `44b into engagement with horizontal surface 33e, and there follows engagement of a suitably formed stop 38h with guidesupport means 30h and disengagement of armature 23b from pole pieces 29b.

Closing the door effects reverse relative movement of the elements, to the position shown in Figure 6, where the follower 44b resiliently urged against cam 33h provides the final closing and holding force of the door thereby suitably compressing the sealing gasket.

It is seen that, in each of the embodiments illustrated, abutting interengagement of the magnetic latch elements takes place prior to compression of the resilient gasket means. Thus the effective force, overcoming the resilience of the subsequently compressed gasket, is provided by the spring-urged mechanical latch. The energy stored in the sealing gasket is of sufficient magnitude to cause the door to rebound and overcome the force between the magnetic latch elements7 which are substantially rigidly mounted to the cabinet structure. However, in the event the door is slammed the energy stored in the compressed gasket is advantageously absorbed by the mechanical latch.

It is also to be appreciated that the resilient nature of the mechanical portion of the latch provides means for cushioning the shock of impact between the magnet and its armature under any degree of forceful closing of the door. Lack of such cushioning has been a major failing of certain magnetic latch devices heretofore known. Still further, the abutting engagement of the magnetic latch elements facilitates assembly of the door to the cabinet, as well as obviating need for vertical adjustment of the aforesaid elements in the event the door should sag.

It is further pointed out that the latch means of the present invention provides the desirable features of a mechanical latch Without need for interlocking elements. The sole attractive force is between abutting magnetic elements and is devoid of any interlocking relationship which may cause wear and jamming of the mechanism. This may be very advantageous in the event of entrapment or other emergency.

While this description and the accompanying drawings are illustrative of several preferred embodiments of the invention, it will be recognized that changes may be made in the apparatus described, without departing from the spirit of the invention as defined in the appended claims.

I claim:

1. Door latching apparatus, comprising, magnetically interengageable latch and keeper means, at least one of which means comprises a magnet and one of which is mounted for movement between two terminal positions, and swinging link means interconnecting such door and the movably mounted means and being operative in response to opening and closing movements of such door, while the latch and keeper means are interengaged, to eect movement of the movably mounted means between said terminal positions, said link means further being operative in response to interengagement of said latch and keeper means to eifect movement of the movably mounted means to one terminal position, whereby to urge the door t0 closed position.

2. Door latching apparatus comprising, magnetically interengageable latch and keeper means at least one of which means comprises a magnet and one of which is mounted for movement between extended and retracted positions, and pivotally mounted link means operative to move the so-mounted means toward its retracted position, in response to interengagement of said latch and keeper means while the movably mounted means is in its extended position, whereby to urge the door to closed position.

3. Apparatus in accordance with claim 2 wherein said pivotally mounted link means includes over-center mechanism disposed and adapted to provide for operation of the said link means.

4. Door latching apparatus comprising, magnetic latch and keeper means adapted for abutting engagement to provide magnetic latching, and swinging link means associated with said latch means and so arranged as to cause the latch means to be moved positively a predetermined distance upon movement of the door and while the said latch and keeper means are engaged, said swinging link means further being operable in response to abutting engagement of said latch and keeper means, to urge the door to closed position.

5. Apparatus in accordance with claim 4 wherein said said swinging link means includes overcenter mechanism disposed and adapted to provide for operation of the said link means.

6. Door latching apparatus, comprising, magnetic latch and keeper means adapted for abutting engagement to provide magnetic latching, one of said means being mounted for extension and retraction movements during abutment of the two means, and a swinging link associated with the movably mounted means to eiect the mentioned extension and retraction movements thereof, said swinging link being operable in response to such abutting engagement to retract the movably mounted means and to urge the door toward closed position.

7. Door latching apparatus, comprising, magnetic latch and keeper means adapted for abutting engagement to provide magnetic latching, one of said means mounted for extension and retraction movemens during abutment of the two means, and resiliently actuatable cam means associated with one of said means, operable in response to such abutting engagement, to retract the so-mounted means and to urge the door toward closed position.

8. Door latching apparatus comprising, magnetically interengageable latch and keeper means, at least one of which means comprises a magnet and one of which is mounted for movement between two terminal positions, and resiliently actuatable cam means adapted to move the so-mounted means toward one terminal position in response to interengagement of said latch and keeper means, whereby to urge the door to closed position.

9. Latch means for cabinet structure having a hinged door provided with a magnetic keeper element, said means including frame means, a latch element slidably supported in said frame means for movement to a fully extended door-open and a fully retracted door-closed latching position and having an inner end and an outer end, said outer end being magnetically engageable with said magnetic keeper while said latch element is in its extended position, a cam surface provided on the said inner e-nd of the latch element, and a resiliently actuatable cam follower operably engaging said cam surface, the construction and arrangement of said cam and cam follower providing a door closing and holding force while the lkeeper and latch elements are magnetically engaged.

10. Door latching apparatus comprising: magnetically interengageable latch and keeper means, said latch means' comprising a magnet having a pair of substantially parallel vertically extending pole pieces, one pole piece of said pair being cooperable with guide means mounting the same and providing for movement of the magnet between extended and retracted positions, and the other pole piece of said pair having a cam formed therein, a resiliently actuatable cam follower for said cam operably engaging the latter, the construction and arrangement of said cam and cam follower providing a door closing and holding force in response to interengagement of said latch and keeper means while the latch is in its extended position.

References Cited in the le of this patent UNITED STATES PATENTS 

